#coding: UTF-8
import math

p = list(map(float, input().split()))
# dis = math.sqrt(pow((abs(p[2]) - abs(p[0])), 2) + pow((abs(p[3]) - abs(p[1])), 2))
dis = math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2))

print(round(dis, 8)) import math math p = list(map(float, input().split())) p list(map(float, input().split())) list map(float, input().split()) map float input().split() ().split () input split dis = math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2)) dis math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2)) math.sqrt math sqrt pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2) pow((p[2] - p[0]), 2) pow p[2] - p[0] p[2] p 2 p[0] p 0 2 pow((p[3]) - (p[1]), 2) pow (p[3]) - (p[1]) p[3] p 3 p[1] p 1 2 print(round(dis, 8)) print round(dis, 8) round dis 8 dis = math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2)) math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2)) dis p = list(map(float, input().split())) list(map(float, input().split())) p
#coding: UTF-8
import math

p = list(map(float, input().split()))
# dis = math.sqrt(pow((abs(p[2]) - abs(p[0])), 2) + pow((abs(p[3]) - abs(p[1])), 2))
dis = math.sqrt(pow((p[2] - p[0]), 2) + pow((p[3]) - (p[1]), 2))

print(round(dis, 8))
